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Developing porous materials for C3H6/C3H8 separation faces the challenge of merging excellent separation performance with high stability and easy scalability of synthesis. Herein, we report a robust Hofmann clathrate material (ZJU‐75a), featuring high‐density strong binding sites to achieve all the above requirements. ZJU‐75a adsorbs large amount of C3H6 with a record high storage density of 0.818 g mL−1, and concurrently shows high C3H6/C3H8 selectivity (54.2) at 296 K and 1 bar. Single‐crystal structure analysis unveil that the high‐density binding sites in ZJU‐75a not only provide much stronger interactions with C3H6 but also enable the dense packing of C3H6. Breakthrough experiments on gas mixtures afford both high separation factor of 14.7 and large C3H6 uptake (2.79 mmol g−1). This material is highly stable and can be easily produced at kilogram‐scale using a green synthesis method, making it as a benchmark material to address major challenges for industrial C3H6/C3H8 separation. [ABSTRACT FROM AUTHOR]

Developing porous materials to overcome the trade‐off between adsorption capacity and selectivity for C2H2/CO2 separation remains a challenge. Herein, we report a stable HKUST‐1‐like MOF (ZJU‐50a), featuring large cages decorated with high density of supramolecular binding sites to achieve both high C2H2 storage and selectivity. ZJU‐50a exhibits one of the highest C2H2 storage capacity (192 cm3 g−1) and concurrently high C2H2/CO2 selectivity (12) at 298 K and 1 bar. Single‐crystal X‐ray diffraction studies on gas‐loaded ZJU‐50a crystal unveil that the incorporated supramolecular binding sites can selectively take up C2H2 molecule but not CO2 to result in both high C2H2 storage and selectivity. Breakthrough experiments validated its separation performance for C2H2/CO2 mixtures, providing a high C2H2 recovery capacity of 84.2 L kg−1 with 99.5 % purity. This study suggests a novel strategy of engineering supramolecular binding sites into MOFs to overcome the trade‐off for this separation. [ABSTRACT FROM AUTHOR]

Porous materials for C2H2/CO2 separation mostly suffer from high regeneration energy, poor stability, or high cost that largely dampen their industrial implementation. A desired adsorbent should have an optimal balance between excellent separation performance, high stability, and low cost. We herein report a stable, low‐cost, and easily scaled‐up aluminum MOF (CAU‐10‐H) for highly efficient C2H2/CO2 separation. The suitable pore confinement in CAU‐10‐H can not only provide multipoint binding interactions with C2H2 but also enable the dense packing of C2H2 inside the pores. This material exhibits one of the highest C2H2 storage densities of 392 g L−1 and highly selective adsorption of C2H2 over CO2 at ambient conditions, achieved by a low C2H2 adsorption enthalpy (27 kJ mol−1). Breakthrough experiments confirm its exceptional separation performance for C2H2/CO2 mixtures, affording both large C2H2 uptake of 3.3 mmol g−1 and high separation factor of 3.4. CAU‐10‐H achieves the benchmark balance between separation performance, stability, and cost for C2H2/CO2 separation. [ABSTRACT FROM AUTHOR]

Separation of acetylene (C2H2) and carbon dioxide (CO2) is of prime importance in the petrochemical industry, but their similarities in molecular size and volatility make it particularly difficult. A desired adsorbent for highly efficient C2H2/CO2 separation should have high selectivity and C2H2 uptake simultaneously, and the introduction of functional groups into MOFs is an effective strategy to achieve this purpose. Herein, we report a titanium‐based MOF material (MIL‐125‐NH2), featuring the suitable pore sizes and amino‐functionalized pore surfaces to show the preferential adsorption of C2H2 over CO2 with both high C2H2 uptake and C2H2/CO2 selectivity. Theoretical simulation results indicate that the preferential C2H2 adsorption is mainly attributed to multiple hydrogen bonding interactions between C2H2 molecule and amino functional groups. [ABSTRACT FROM AUTHOR]

Separation of propyne/propylene (C3H4/C3H6) is more difficult and challenging than that of acetylene/ethylene (C2H2/C2H4) because of their closer molecular sizes. A comprehensive screening of a series of metal–organic frameworks with broad types of structures, pore sizes, and functionalities was carried out. UTSA‐200 was identified as the best separating material for the removal of trace C3H4 from C3H4/C3H6 mixtures. Gas sorption isotherms reveal that UTSA‐200 exhibits by far the highest C3H4 adsorption capacity (95 cm3 cm−3 at 0.01 bar and 298 K) and record C3H4/C3H6 selectivity, which was mainly attributed to the suitable dynamic pore size to efficiently block the larger C3H6 molecule whilst the strong binding sites and pore flexibility capture smaller C3H4. This material thus provides record purification capacity for the removal of C3H4 from a 1:99 (or 0.1:99.9, v/v) C3H4/C3H6 mixture to produce 99.9999 % pure C3H6 with a productivity of 62.0 (or 142.8) mmol g−1. Record removal: A series of metal–organic frameworks with broad types of structures, pore sizes, and functionalities were used to identify UTSA‐200 as the best separating agent for removal of trace C3H4 from C3H4/C3H6 mixtures. The efficiency is mainly attributed to the optimally dynamic pore size to efficiently block the larger C3H6 whilst retaining strong binding sites to selectively take up C3H4, thus producing high‐purity C3H6 (99.9999 %). [ABSTRACT FROM AUTHOR]

• Unique pore structure enables the dense packing of Xe inside the pores. • Both high Xe sorption capacity and Xe/Kr selectivity are achieved. • The highest Xe storage density at ambient conditions. For adsorptive separation of xenon/krypton mixture, it still remains a daunting challenge to target both high Xe adsorption and selectivity in a single adsorbent because of their close size and inert nature. Herein, we report an ultra-microporous alkyl Cu-based MOF-11 with suitable pore architecture for benchmark Xe capture and separation. MOF-11 features small pore channels (4.4 Å) close to the kinetic diameter of Xe, in which a large number of alkyl cavities and oppositely adjacent open Cu-metal sites are densely arranged along the pore channels in staggered mode. Such unique pore system can not only introduce strong binding affinity with Xe, but also enable the dense packing of Xe inside the pores. This material shows the highest Xe storage density of 2826 g/L at ambient conditions, record-high Xe uptake (4.0 mmol g−1at 0.2 bar and 298 K) and one of the highest Xe/Kr selectivity (19.1). The Xe locations within MOF-11 were visually identified by single-crystal X-ray diffraction experiment, which unveils the dense packing mechanism of Xe within the pores accountable for the record Xe capture capacity. The breakthrough experiments confirm that MOF-11 exhibits the exceptional separation performance for 20/80Xe/Kr mixture with both record-high Xe uptake capacity (3.46 mmol g−1) and Kr productivity (350 cm3 g−1). [ABSTRACT FROM AUTHOR]